A4000 Mouse problem

[Webba]

Hello eveyrbody!

I just registered here even though I have been reading this site for years now. Thanks for all the hard work keeping this site running.

To the point...

My old A4000 has become unusable during last winter. First it started much earlier by the mouse not moving in horizontal directions very well. After cleaning the mouse and buying two new ones I had to believe it is a hardware failure inside the box. I have earlier bought a Punchinello PC serial mouse adapter and that seemed to work quite OK for a while even though original Amiga mouses weren't.

Later on this spring the mouse stopped working completely. I tried the other port with proper software also with no success. Now I am forced to use my wintel machine for all things

Has anybody any clue what could it be?
I have tried searching the Google groups and found some similiar cases one stating that I should change some chip U975 on the mainboard.
I have a friend who can do it but is that going to fix it?

I wouldn't want to waste it quite yet since Its going to have the OS4 before the AmigaOne sitting next to it. And the setup is quite usable except this problem.

Webba

[tonyw]

Webba, I'd check two things:

1. Is it clean inside? I don't mean drop the ball out and clean it, I mean remove the screws and take the lid off. You will probably find all sorts of fluff and crap inside. Get it all out with compressed air at the local garage. Make sure that the little wheels all have clean slots. Make sure that the shafts on which the ball rides are clean, not covered in hair and fluff.

2. While you've got it open, plug it into the mouse port and check that rotating the wheels by hand (gently) moves the mouse pointer up/down and left/right. If it doesn't. I'd think about cutting off the end of the cable a few cm away from the mouse and re-terminating the cable. But that's a bit drastic if you don't have the proper tools.

tony

[Webba]

OK,

Got just back from visiting the office, nice working hours on the IT sector, from 0015 AM to 3 AM when customer calls. Well I will be a bit late in the morning for sure.

Well to the point again.

Maybe I didn't make myself clear enough. I have done pretty much everything with the mouses including close to that you suggested. And like I said I have also bougth new mice and tested them on other computers, all working perfectly on those.
I was just too lazy to write down all the stuff I have done.

I am 99,99% sure that the problem is inside the A4000 not in the mice.

Good night,

Webba

[csirac_]

It certainly does sound like your A4k motherboard. Especially if you rbattery is leaking.

You could always buy a USB board and wait for OS4, then use a USB mouse

- Paul

[Edit - if your RTC battery *IS* leaking, clean it up and replace the battery ASAP]

[Cass]

Well I will be a bit late in the morning for sure.

Isn't there a 6 months day & a 6 months night? (how you can tell by looking the sky if it's morning or dusk?!) :-)

Now the answer:
Might be a burnt CIA ?! Those get busted frequently by trying to plug-unplug the joysticks or the mouse. There are 2 of those on the motherboard (CIA-ODD & CIA-EVEN , code 8520?). You could put one in the place of the other (exchange them), just to see if the problem is resolved (but keep in mind that it's not a permanent solution, since you could get other problems) and if so, you could buy a new one for replacement (they shouldn't cost much, or you may get one from an old A500).

Also check the plug on the motherboard (any bent pins etc.)

________
Weed Bubblers

[Webba]

Well well,

I have changed the battery about three years ago and it wasn't leaking at the time.
So thats not the problem.

Then the CIA might be, but I seen so many posting in Google groups saying that the
CIA isn't the problem in these cases.

Any other suggestion??

Webba

[boisterous]

I had this problem on my a4000/040 a couple of years ago, and pinned it down to the cpu overheating and lifting the daughterboard.
A cpu cooler fixed all traces of the problem.

[Webba]

Interesting...

I doubt that too, since my Cyberstorm PPC 060/233 is running quite cool because of the selfmade cooler hack. I have a heatsink even on the 060 and a 80mm fan blowing on top of the sinks.  That's because the original PPC fan wasn't that long lasting, less than a year with 24/7 usage.

That's the case with most fans if you don't buy some higher quality fans. It is well worth paying double the price compared to the cheapest ones, since you don't have to change the fan every six months. I have learnt that during the last fe years.

Webba

[Cass]

One more suggestion:
Try to measure the voltage of the mouse port (check the schematics for the pin-out, 5V & Ground) with a tester. If it's dead, look the motherboard near the port for a burnt resistance or capacitor.
If it was a PSU problem you would have more serious problems.

I'm still for the CIA problem (it costs you nothing to exchange them, but I'm not sure if it's easy as in a A500, which are on a socket), because it's the controll system of mouse & joyport.

________
Bbw model

[Webba]

Ok,

I didn't remember to mention that either, just did that two weeks ago and the voltage is allright in both ports. Actually my board is on my worktable in static safe back waiting for operation. Exchange on the U975 component that somebody in old newsgroups said might help. My friend works in electronics company that has the needed equipment to make exhange.

I just wanted to see if somebody here knows any other things to try or maybe comfirm the exchange of that component 74HCT166D.

And the CIA thing would be easy if they were socketed, but unfortunately only thing socketed on my A4000 is the SuperBuster.


Webba